Whoopee Cushions
by stars-of-february
Summary: If there's one day of the year that Sans loves the most, it's the first of April. What's at the top of his list? Punking his brother Papyrus, of course.
1. Whoopee Cushions

He slid swiftly out of bed, taking care not to be too loud. Heaven forbid that Papyrus should wake up to the sound of pattering feet and the muffled sounds of Sans' deep, infectious laughter.

Sans had a perfectly good reason to be laughing, anyway. Today was the one day of the year that he put any effort into, besides Pap's birthday.

April Fools!

The one day of the year that made any prank, even the drop-dead worst, passable with those two words.

Snickering to himself, Sans padded down to the kitchen, carefully opening one of the cupboards. Over the months leading up to the special day, he had stocked up an impressive amount of trick goodies; from the loudest and vilest whoopee cushions, rolls of saran wrap (which could be surprisingly useful for a variety of mischief), containers filled with hot sauce, ketchup and fake blood, small spray bottles brimming with a fascinating thing called "Liquid Ass" (do not try at home), soap bars, various fruit peels, a couple of bones that the strange little white dog sometimes stole from them, greenish slime, a variety of plastic critters and zillions more, all tucked away behind a bunch of dusty, broken kitchen appliances that Papyrus kept in the hope that he would someday remember to ask Alphys to fix them all.

Perusing his sizable collection, he decided to start simple. Sans grabbed a roll of the shiny saran wrap and silently climbed the stairs back to Papyrus' room, shaking with laughter.

Stretching the gigantic roll from one end of the door frame to the other, he continued in a zigzagging fashion until a shining curtain of plastic covered the entrance to the poor skelebro's room. Knowing Papyrus, the overzealous, lanky skeleton would likely dash out the door without a second thought and end up hopelessly entangled in a plethora of plastic wrap. Just to top it off, he also placed a couple of banana peels on the ground to trip Papyrus up as he would try to fight his way out of the death trap of a door. Sans almost felt sorry for him, but brushed it off. Papyrus wasn't an exception to his shenanigans, and he proved this every day by plaguing him with an endless barrage of terrible puns and excruciatingly awful jokes. However, Papyrus was coming close to developing an immunity to them. Almost.

Sans stepped back and admired his handiwork for a moment, feeling quite proud of himself, even if he had just simply stuck a swath of plastic onto a door frame. A prank was a prank, and what mattered was the reaction and the outcome. And he was sure that the reaction he was going to get out of Papyrus was going to be priceless, with a capital "p".

Chuckling quietly to himself, Sans strolled down to the kitchen and heated up a little water, wanting a good cuppa to start his day. He riffled through piles of Papyrus' cooking ingredients (some of which included expired tomato sauce and broken dry pasta) and finally managed to unearth a bag of coffee grounds. Dumping some into a mug, he spooned in some sugar and took the kettle off the stove, which was currently emitting puffs of steam and whining a little. Sans carefully poured the hot water into the mug, stirring it with a spoon slowly.

As he drank his (black) coffee, Sans stared out the window of his and Papyrus' little home. Small shafts of sunlight shone in the glass windows, and the sky was tickled with little streaks of baby pinks and soft yellows. Only then did Sans realize how early he had woken up. It seemed like almost a criminal offense in Sans' book: waking up early. He couldn't believe himself, but then again, it was April Fools', and therefore an occasion worshiped by Sans.

"GOOD MORNING, MY DEAR BROTHER- NYEEAAAAAAHHHHHHH!"

There was a great deal of indignant "nyeh"s, the sound of clattering bones, shrieks of shock and cries of "SAAAAAAAAAANS!" as the poor skeleton was waylaid by a web of saran wrap, rows of neatly placed bananas, and his long and clumsy limbs.

Sans doubled over in laughter as his helpless brother tumbled blindly down the stairs and finally bounced to a stop in their now-wrecked kitchen, sprawling in rotten banana peels and torn-up pieces of the plastic Sans had stuck in his door, not to mention the piles of broken dry pasta strewn across the floor after Papyrus' spectacular fall. Papyrus wailed comically as he struggled to drag himself up, but to no avail. The wrap had pretty much tangled his legs together and held fast despite his best efforts, not to mention the stray banana peels stuck on his skull.

"S-SANS..." whined Papyrus, obviously resigned and more than a little annoyed. "PLEASE ASSIST ME IN REMOVING MY UNYIELDING BODY FROM THIS MONSTROSITY."

Sans grinned mischievously and strolled off. "april fools, bro."

One down, plenty more to go.

* * *

 _A/N: The female author in her natural habitat sneaks around in her Works section of her Wattpad account, seeking the rare thing called "the unfinished story"..._

 _Yeah, and that's how I got this one. Whoopee Cushions was meant to languish for all eternity in a sloppy, badly-written outline after I missed April Fools, since I wanted this out by then. The original story was supposed to be a hell lot bigger than this, but I decided to cut it short and let you guys imagine what other shenanigans continue from there._

 _Anyway, hope you all liked this (very) short story! I wanted to give you a little something since you guys must be itching for the new chap of The Gourmet... PUT THAT AWAY, IT'S COMING, OKAY? Just wait till next Tuesday, gosh..._

 _Love you all,_

 _Meikai_


	2. I Dare You

Description: After Pacifist (if you choose to stay), the Undertale gang decides to play a casual game of WUSS, which is like HORSE except it involves dares, and passing a dare gets you a letter. Who wins? Caution: slightly disgusting.

P.S: Please, if you can... sing along with Undyne, okay? Thanks.

P.P.S: The stick figure me + troll face indicates that this chapter will be trollish and immature.

"ALRIGHT, IS EVERYONE READY?" shouted Papyrus exuberantly. Everyone nodded or uttered some form of assent (Undyne screamed unintelligibly, while Frisk nodded silently). A hand-knitted hat of Papyrus' lay on the table in front of Frisk, Napstablook, Sans, Papyrus, Undyne, Alphys, Mettaton, Toriel and Asgore, full of slips of paper. On each and every slip of paper, all of the monsters and lone human present had written a variety of dares for each other, from the most gruesome to the very tame. The group of friends was exchanging bets for the winner, the plucky ones betting for themselves and the less bold betting on others. Not surprisingly, the most popular ones were Undyne, Asgore and Frisk.

"now then," said Sans in his deep, baritone rumble. "i'm sure you're all aware of the rules. we all take turns drawing from pappy's hat and choose whether we want to do the dare on the paper we get or pass. passing quice... or four times... oh, whatever. passing four times means you're a W-U-S-S. a wuss. then you lose. last person still standing wins. we clear?"

Despite the casual situation, Sans still managed to sound intimidating, especially with his naturally low voice. There was a collective shiver, and then Mettaton cleared his throat pointedly. "Crystal," the elegant robot said politely.

"OKAY! THANK YOU FOR THAT QUICK RULE RECAP, SANS," said Papyrus, shooting a look at his short skelebro. "ALSO, AS A PRIZE, THE WINNER OF THE GAME WILL RECEIVE A MONTH'S SUPPLY OF MY FAMOUS SPAGHETTI!"

There was a collective sigh at this. Papyrus was not exactly the spaghetti connoisseur he claimed to be. Regardless, everyone was used to the taste of under-cooked pasta, watery tomato sauce and burnt meatballs.

"and, uh," Sans interjected. "a free 500 g meal at grillbz."

As soon as the words had left Sans' mouth, there was utter pandemonium. Undyne flipped the table and roared, "YOU'RE ON, BUDDY!" Alphys flushed and muttered that she was a vegetarian and couldn't eat those things. Papyrus sighed dramatically at Sans and said, "YOU ARE MUCH TOO ENGROSSED IN THE WORLD OF FAST FOOD, MY DEAR BROTHER."

"ALRIGHT, ALRIGHT!" yelled Papyrus over the din. "LET'S NOT GET TOO ROWDY YET! WE'VE GOT LOTS TO DO!"

Eventually, everyone settled down after Undyne managed to reattach the broken table leg with sheer brute force and Frisk calmed down a teary Napstablook, who insisted that he could not win and would rather not participate. (He participated anyway.)

After a quick draw to determine who would go first, Toriel was chosen to be the first one to draw a dare. She nervously inserted a furry white paw into Papyrus' hat, rummaged around a bit and finally withdrew her piece of paper.

 _"Eat a whole jar of mustard."_

Toriel shrugged. "I suppose that cannot be too bad."

The gang of friends crowded around the kindly goat monster as Papyrus carefully handed her a glass jar filled with bright yellow mustard. It was still unopened and brimming with the strong-smelling condiment. "MMM..." Papyrus grinned encouragingly. "GOOD LUCK, ASGORE'S CLONE!"

Alphys passed Toriel a spoon as she stared down the jar. With a quick flick of her paw, she twisted the top off and inhaled the smell. She daintily dipped the spoon into the jar and licked it carefully.

"Not bad." Toriel commented. She took a spoonful this time, swallowed it and paused a moment to let it sink in.

"HURRY UP, TORI!" yelled Undyne. "We haven't got all day, ya know!"

Toriel shrugged. "Rushing myself might result in less-than-favorable circumstances."

Five minutes later, Toriel was just barely halfway through the jar. Undyne was grumbling audibly, Papyrus was shifting around with pent-up energy and Sans had fallen asleep. Even Asgore had to suppress a yawn or two. Bit by bit, the jar of mustard finally dwindled down to a small amount. Toriel had to sniff a couple of times, overwhelmed by the sourness and the powerful fumes.

Finally, Toriel scraped the last few smidgens of mustard off the jar and set it down. "I'm done," Toriel smiled.

Everyone sighed in relief. "I thought we were gonna be here FOREVER!" chortled Undyne as she punched Toriel on the shoulder, nearly knocking her flat on the ground. Toriel then toppled onto Asgore, who fell on Undyne, who crashed into Papyrus, who promptly broke a vase.

After a moment of silence, Papyrus shifted uncomfortably and muttered an apology. In an instant, Sans' eye flashed blue protectively, daring anyone to blame Papyrus.

"undyne."

"Yeah, punk?!"

"say sorry to everyone."

"HUH?! What did I do?!"

Sans looked at her, blue eye flaring threateningly. "lemme repeat myself: you're gonna say sorry, and you're gonna do it now."

Undyne froze, reaching for her spear instinctively before realizing where she was.

"Uh... I mean, SORRY, GUYS! Jeez, Sans, take it easy..." grumbled Undyne.

Sans relaxed and everyone shuddered in relief, except for Papyrus, who was scolding Sans.

"CAN WE CONTINUE NOW? PLEASE?" Papyrus pleaded, putting on his puppy dog face.

"FINE!" yelled Undyne. "I'M GOING NOW!"

Undyne grabbed the hat roughly, shook it so hard that papers went flying in every direction, and yanked a crumpled piece of paper with such force that it tore in two. She slammed the pieces together so hard that they somehow fused back together. Her bright eyes scanned the slip of paper carefully and nearly shrieked out her dare.

 _"SING THE SONG 'Y.M.C.A" AS LOUD AS YOU CAN IN THE MIDDLE OF SNOWDIN TOWN! ^_^"_

"HAH!" cried Undyne. "I can do that!"

Sans shrugged. "let's see you do it, tough gal."

Undyne jumped up so aggressively that the couch toppled over and smacked Papyrus on the noggin. Immediately Sans was at his side, almost as if he had teleported over.

"paps, you okay, buddy?" Sans muttered, giving him a frantic once-over. Papyrus, evidently confused, gave Sans a blank look.

"oh no!" yelled Sans, grabbing Papyrus by the shoulders.

"BROTHER?"

"papyrus, please!"

"BROTHER, I'M-"

"no... no..."

"SANS!"

Sans blinked once. Then twice. Then sighed.

"god, papyrus, you scared me..."

Papyrus grinned. "YOU'RE A WEIRDO, YOU KNOW THAT, BIG BROTHER?"

Undyne screamed impatiently. "LET'S GOOO! Stop with this cheesy, overdone bro-ment!"

She herded the gaggle of friends outside of Sans' and Papyrus' home and into the town square, where she cleared her throat loudly. Townsfolk stopped to look curiously.

"LISTEN UP, YOU PUNKS!" yelled Undyne. "I'm gonna SING for you all, so YOU BETTER," she paused and unsheathed her spear threateningly, "LISTEN," she brandished her weapon around, "TO ME!"

Confused, monsters gathered round, awaiting her musical performance.

And she opened her mouth to sing.

And oh, what a voice it was.

Gravelly-sounding but also strangely melodic, she churned out the lyrics with a rough and twangy voice, similar to the likes of a female Tom Waits, but with less Cookie Monster undertones.

 _Young man, there's no need to feel down_  
 _I said, young man, pick yourself off the ground._  
 _I said, young man, 'cause you're in a new town_  
 _There's no need to be unhappy_

Alphys, to her credit, started clapping along timidly to the beat. Papyrus followed suit, and soon the whole crowd began tapping along to the rhythm.

 _Young man, there's a place you can go._  
 _I said, young man, when you're short on your dough_  
 _You can stay there, and I'm sure you will find_  
 _Many ways to have a good time_

Undyne stomped her feet, getting into the song. BOOM, BOOM, BOOM, BOOM, BOOM...

And then the chorus kicked in, with monsters shouting along:

 _It's fun to stay at the Y.M.C.A_  
 _It's fun to stay at the Y.M.C.A_

Undyne threw her head back and wailed the next few lines.

 _They have everything for you men to enjoy,_  
 _You can hang out with all the boys..._

The crowd swayed to the beat, crying the lyrics out with wild abandon.

 _It's fun to stay at the Y.M.C.A_  
 _It's fun to stay at the Y.M.C.A_

Undyne swung her hair from side to side, basking in the glory of the performance.

 _You can get yourself clean, you can have a good meal,_  
 _You can do whatever you feel..._

Suddenly, Papyrus began singing along, softly at first, until his high and warbling voice resonated along with Undyne.

 _Young man, are you listening to me?_  
 _I said, young man, what do you want to be?_  
 _I said, young man, you can make real your dreams._  
 _But you got to know this one thing!_

Undyne spun around dramatically, hissing the lyrics out with a passion that had never been seen before as Papyrus sung backup.

 _No man does it all by himself_  
 _I said, young man, put your pride on the shelf,_  
 _And just go there, to the Y.M.C.A_  
 _I'm sure they can help you today_

This time, the entire crowd stomped, a loud _BOOM, BOOM, BOOM, BOOM, BOOM_ right before the chorus.

 _It's fun to stay at the Y.M.C.A_  
 _It's fun to stay at the Y.M.C.A_

"SING IT!" yelled Undyne, and Papyrus stepped right in the middle of the crowd in front of Undyne and sang at the top of his lungs.

 _You can get yourself clean, you can have a good meal,_  
 _You can do whatever you feel..._

 _Young man, I was once in your shoes_  
 _I said, I was down and out with the blues_  
 _I felt no man cared if I were alive_  
 _I felt the whole world was so jive..._

Undyne jumped back in, serenading the crowd with her gritty voice.

 _That's when someone came up to me,_  
 _And said, young man, take a walk up the street_  
 _There's a place there called the Y.M.C.A_  
 _They can start you back on your way_

Crowd roaring, Undyne and Papyrus took deep breaths and belted out the final few lyrics, with Undyne singing some lyrics and Papyrus singing others.

 _It's fun to stay at the Y.M.C.A_  
 _It's fun to stay at the Y.M.C.A_

 _They have everything for you men to enjoy,_  
 _You can hang out with all the boys..._

 _Y.M.C.A...you'll find it at the Y.M.C.A_

 _Young man, young man, there's no need to feel down_  
 _Young man, young man, get yourself off the ground_

 _Y.M.C.A...you'll find it at the Y.M.C.A_

 _Young man, young man, there's no need to feel down_  
 _Young man, young man, get yourself off the ground_

 _Y.M.C.A... just go to the Y.M.C.A_

 _Young man, young man, are you listening to me?_  
 _Young man, young man, what do you wanna be?_

As the song drew to a close, the crowd literally surged forward and buried Undyne and Papyrus with hugs and kisses and autograph requests and shouts of joy and pleas for encores.

Eventually, Undyne resurfaced from the swarms of monsters, dragging Papyrus with her, who was signing autographs six at a time.

"Thanks, guys, but we gotta go," she repeated over and over, her voice getting gruffer as she continued to push through the crowd. Evidently, she didn't want to leave as much as she was trying to look like, but Undyne also knew that Papyrus wouldn't leave, at least for not several hours signing every autograph and talking to every individual.

The two found their little group of friends waiting in the fringes of the massive gathering of monsters. Alphys hugged Undyne happily, which made the red-haired warrior flush a deep crimson while Sans quietly congratulated his brother for his impromptu duet. The rest of the group was full of praise for the duet, and Napstablook even shyly asked Undyne and Papyrus if they wanted to collaborate sometime.

After they finally staggered home, Undyne laughed a little, shaking her head. "Who woulda thunk, huh, Paps?"

"NONSENSE," Papyrus gasped. "UNDYNE, I MUST TELL YOU, THOUGH I DID A FINE JOB OUT THERE, IT WAS ALL YOU, DEAR FRIEND. IT WAS YOUR DARE, AFTER ALL! MY HEARTIEST CONGRATULATIONS, UNDYNE!"

Undyne grinned, a blush fighting its way back onto her scaly cheeks. "Thanks, man. Means a lot."

"alright, alright, let's keep moving. whose turn?" blurted Sans.

Everyone looked at each other, then looked at Sans.

"fu- i mean, f-fine, i'll go." Sans shuffled the paper around until he picked up a tightly folded slip.

 _"Say: I am a big dumb dick."_

Sans looked at the slip. The slip looked back.

"WHAT DOES IT SAY, BROTHER?" Papyrus exclaimed, as full of enthusiasm as ever.

Undyne laughed. "HA! It says- MMPFF!"

Toriel had effectively stopped Undyne's loose tongue by stuffing a paw in front of her mouth and Sans was literally spluttering with anger.

"h-how dare you..." he managed.

Undyne began to sweat profusely and quickly excused herself to the washroom, leaving a confused Papyrus and triumphant Sans.

"welp," Sans said as soon as Undyne scrambled away. "i think i'll pass."

Everyone stared.

Asgore raised his bushy, blond eyebrows. "Sans, you must be joking. Regardless of its vulgarity, it's an easy one."

"eh. to be honest... i'm really quite bone-tired."

Everyone collapsed and groaned comically. Sans' puns were literally the worst things to ever exist in the Underground, and this time, it was even worse with the fact that Sans was passing a dare that even shy Alphys could've done easily.

"VERY WELL, SANS," Papyrus said awkwardly. Sans seemed undisturbed by the reactions he was getting. On the contrary, he seemed rather amused by everyone's shock.

"so who wants to go next, then?" Sans asked lazily. He eyed the group of monsters and smiled. "how 'bout ol' Alphys?"

The shy yellow dinosaur looked up and fiddled with her lab coat. "Uhm... I mean... y-yeah, sure...?"

At that moment, Undyne burst in and yelled, "C'MON, ALPHYS! I know you can do it!"

Alphys blushed so much, she appeared to be more red than yellow. "T-thanks, Undyne... uh, I guess... yeah, I'll go!"

She dug out a piece of paper from the hat and quickly examined it before reddening even more so that she resembled a dinosaur comprised mainly of tomatoes.

 _"Kiss the person to the right of you!"_

Alphys glanced over. She was sitting on the floor of the skelebro's house, next to the kitchen, which... Undyne... had just... appeared... and she was still... standing there... to the right of her...

Alphys' vision grew fuzzy at the edges and before she knew it, she had passed out.

"Man!" Undyne squawked. "What was so bad about that dare that she passed out?"

Everyone exchanged looks, which made Undyne mad, and being mad made her itch for her spear, which she took out and smashed through the floor.

"YOU GUYS!" Undyne sighed. "I'm missing something, huh?"

"Yeah..." Napstablook murmured unhappily.

"SHUT UP, GHOST!" screamed Undyne. Napstablook whimpered and floated away.

"Undyne..." chided Mettaton. "Blooky is upset now thanks to you."

"YEAH?" yelled Undyne. "I'LL GIVE YA UPSET!"

Suddenly she leaped and drove two more spears in the floor of Sans' and Papyrus' house. Incensed, Sans attacked with Gaster Blasters. Papyrus got in the way and consequently died. Frisk went insane trying to stop them and suffered from irreversible brain damage later. Mettaton damaged his legs in the ensuing debris and later committed suicide. Alphys and Undyne attempted to run but were killed by the self-sustaining trash tornado that came out of Sans' room since the entire little house was collapsing. Sans somehow got out alive but was killed by a stray bone of his shortly after. Asgore and Toriel were the only ones that got out alive, but Asgore quickly resigned from being king, made the Underground a constitutional monarchy and lived the rest of his days in the Ruins with Toriel, who reconciled with him but eventually returned to the Underground to become prime minister. After a couple of years, the stress got to Toriel and she left and lived with Asgore on a tentative and rocky friendship. Unfortunately, after several years of somewhat peace, the two mysteriously disappeared without a trace...

 _A.N: I have no words for this piece. It got a little too serious near the end so I spiced it up with a troll ending. So yeah._

 _Also if you don't like this troll ending, I might add an alternate ending, but woah, I'm spent from writing this._

 _There you go: a troll chapter for Whoopee Cushions. How appropriate for this trash collection._

 _Love you all,_

 _Meikai_


End file.
